In an in-cell type touch screen, in order to prevent a display operation and a touch operation from interfering with each other, a currently typical method is to drive the display operation and the touch operation in a time division manner during a duration for displaying a frame, and to make a scan frequency of the display operation and a scan frequency of the scan operation to be the same, or to make the scan frequency of the touch operation to be twice of that of the display operation. As shown in FIG. 1, TSVD is a frame synchronization signal for a touch scan operation, and TSHD is a horizontal synchronization signal for the touch scan operation. In the related art, when both the TSVD and the TSHD are at a low level, a display scan operation is performed; when the TSVD is at the low level and the TSHD is at a high level, the touch scan operation is performed; when the TSVD is at the high level and the TSHD is at the low level, the display scan operation is performed; and when both the TSVD and the TSHD is at the high level, neither the display scan operation nor the touch scan operation is performed, but display data signal noise, power supply interference noise, and/or thermal noise are captured as noise pulses which are loaded to a transmitting terminal of a touch sensor. A receiving terminal of the touch sensor receives feedback signals and sends them to a processor for processing, and a period TTSVD of the TSVD is equal to the duration for displaying a frame. In such a case, the scan frequency of the display operation and the scan frequency of the touch operation are the same. In FIG. 1, Display is a display data signal, TX1 is a first touch scan line, TX2 is a second touch scan line, TXM is an M-th touch scan line, and the in-cell type touch screen (display panel) includes M touch scan lines, where M is a positive integer larger than 2.
Because the duration for displaying one frame is relatively constant, the time for driving a screen to display is required to be long enough, and the time for the display operation becomes longer and longer with a resolution being increased, the time for the touch operation becomes shorter and shorter. However, as peoples require a touch response speed to be faster and faster, a higher touch driving frequency is needed (more touch time is needed).